Dead Simple Email

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate readOnlyHint=false and destructiveHint=false. The description adds that it returns details but does not discuss permissions or side effects beyond creation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is very concise, with only necessary information: purpose, return value, and parameter documentation. No wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description is fairly complete for a simple creation tool with output schema and annotations. It explains what it does and parameter meanings, but lacks error conditions or prerequisites.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so description must compensate. It clearly explains each parameter with examples (e.g., 'Support Bot' for display_name, 'support,production' for tags), adding meaning beyond schema titles.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it creates a new inbox and returns details including email address, using specific verb and resource. It distinguishes from sibling tools like delete_inbox and list_inboxes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No explicit guidance on when to use this versus alternatives like sending emails or forwarding. Usage is implied from the name but not elaborated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already set destructiveHint=true and idempotentHint=true. The description reinforces the destructive nature but does not add new behavioral context (e.g., irreversibility, permissions, or error scenarios). It meets the baseline but offers no extra value.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise: two sentences plus a compact parameter listing. Every part is essential and front-loaded, with no redundant information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (one required parameter, output schema present, annotations cover safety), the description is mostly complete. It could mention that deletion is irreversible, but overall it provides enough context for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description must explain the parameter. It explicitly states 'inbox_id: The inbox ID to delete', clarifying the purpose beyond the schema's generic title. Could be more detailed (e.g., format, source), but it's sufficient.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb 'delete' and the resource 'inbox', specifying that it also deletes all messages. This distinguishes it from sibling tools like create_inbox or list_inboxes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives (e.g., when to delete vs. archive, or prerequisites). The description only states what it does, not when or why an agent should invoke it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate the tool is not read-only (readOnlyHint=false) and not destructive, but the description adds no further behavioral context. It does not disclose side effects, permissions, attachment handling, or rate limits, leaving the agent to infer behavior from the name alone.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured as a bullet list of parameter explanations. Every sentence adds value, with no wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the tool's purpose and all parameters adequately. However, given the presence of many sibling tools and no output schema details (though output schema exists), it lacks usage context and behavioral completeness, making it merely adequate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Despite 0% schema description coverage, the description explains each parameter beyond the schema titles. It clarifies that 'inbox_id' identifies the containing inbox, 'message_id' is the message to forward, 'to' accepts comma-separated emails, and 'body' is optional. This adds meaningful semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function ('Forward a message to new recipients') with a specific verb and resource. It distinguishes itself from sibling tools like reply_to_message and send_email by focusing on forwarding an existing message.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for forwarding but provides no explicit guidance on when to use this tool versus alternatives (e.g., reply_to_message, send_email). The comma-separated format for 'to' is mentioned, but no when-not or scenario pointers are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds value by specifying the return metrics (inboxes, emails, plan limits), which is behavioral context beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single sentence that is front-loaded with the core purpose and includes specific details. No unnecessary words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has no inputs, an output schema exists (though not shown), and the description lists key metrics, it is fairly complete. Could note that it returns current status, but still adequate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There are 0 parameters, so the description does not need to explain them. The baseline for no parameters is 4, and the description does not undermine that.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb 'Get' and resource 'account usage metrics', and lists specific metrics (inboxes, emails, plan limits). It distinguishes this tool from sibling tools which are all email/inbox operations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implicitly indicates when to use (to retrieve account usage metrics) but does not explicitly state when not to use or mention alternatives. However, the purpose is clear enough for an agent to select appropriately.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint. The description adds behavioral details: waiting for new email, auto-extracting code and magic link, and mentioning timeout. No contradictions with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, with a front-loaded summary and structured argument list. Every sentence adds value, no extraneous content.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool has 3 parameters and an output schema. The description covers the main behavior and parameters sufficiently. Some details like return format could be expanded, but given the complexity, it is complete enough.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has 0% description coverage, but the description provides an 'Args' block explaining each parameter (inbox_id, from_contains, timeout_seconds) with clear semantics. This adds value beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool waits for a verification/OTP email and returns the extracted code. It uses specific verbs ('Wait', 'return') and identifies the resource. It distinguishes from siblings like 'get_verification_link' and 'wait_for_email' by specifying it extracts codes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Perfect for autonomous sign-ups', providing clear context. However, it does not contrast with alternative tools like 'get_verification_link' or specify when to avoid using this tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive hints. The description adds meaningful behavioral context: it waits for an email (polling), supports a timeout parameter, and extracts a link. This goes beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise: one sentence for purpose followed by parameter explanations. Front-loaded with the core action, no fluff. Every sentence contributes value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a relatively simple tool with an output schema (presumably documenting the return format), the description covers waiting behavior and parameter semantics adequately. It lacks details on failure cases (e.g., timeout), but overall it is sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate. It explains all three parameters: inbox_id (inbox to watch), from_contains (only match senders), timeout_seconds (max seconds to wait, default 60). This adds meaning beyond the schema titles.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool waits for an email and extracts a magic link/verification URL, which is a specific verb+resource pair. It distinguishes from siblings like get_verification_code (returns a code) and wait_for_email (no extraction).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage when expecting a magic link but does not explicitly state when to use this tool over alternatives like get_verification_code or wait_for_email. No when-not or exclusion criteria are provided.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and destructiveHint=false. Description adds paging behavior via 'limit' parameter, but no further behavioral details (e.g., empty results).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Extremely concise: one-line purpose and one-line parameter description. No wasted text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With output schema present and clear annotations, the description sufficiently covers the tool's function and parameters for a simple list operation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, but description explains the 'limit' parameter's meaning ('Maximum number of inboxes to return (default 20)'), adding value beyond the schema's default value.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states the action 'List all email inboxes in the account.' Distinguishes from siblings (create, delete, etc.).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool vs alternatives like create_inbox or list_threads. Missing context for selective usage.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, which cover safety and idempotency. The description adds that limit defaults to 10, but this information is partly inferable from the schema. No additional behavioral traits like pagination behavior, ordering, or threading details are disclosed. The annotations carry the transparency burden effectively.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is very concise: one sentence for the main purpose and two more for parameters. It is front-loaded with the purpose. However, the parameter descriptions could be integrated into the main sentence or formatted more cleanly. Overall, little wasted text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is an output schema present, so explaining return values is not required. The tool has low complexity (2 params, non-destructive). The description covers the basic purpose and parameters but does not mention sorting order (e.g., chronological), whether threads are complete or summarized, or how pagination works beyond the limit parameter. Given annotations and output schema, it is adequate but could be more complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate. It provides labels for both parameters: 'The inbox to list threads for' and 'Maximum number of threads to return (default 10)'. This adds context beyond the raw schema keys, but it does not explain constraints (e.g., valid inbox_id format, limit min/max) or behavior when limit is exceeded. The default value is useful.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the verb 'List', the resource 'conversation threads', and the scope 'in an inbox'. It is distinct from sibling tools like read_thread (which retrieves a single thread) and list_inboxes (which lists inboxes).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not provide any guidance on when to use this tool versus alternatives. It lacks explicit context such as 'use this to get an overview of threads in an inbox' or 'use read_thread for details on a specific thread'. No when-not-to-use or alternative recommendations are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint, so agent knows safety profile. Description adds 'full body content' beyond annotations. No contradictions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Extremely concise: one sentence plus arg list. Front-loaded with purpose, no redundant text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Simple tool with output schema and annotations; description covers core function and args. Could mention authentication or scope, but overall sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema properties lack descriptions (0% coverage). Description's args section provides meaningful explanations for inbox_id and message_id, compensating for schema gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states 'Read a single message with full body content', using specific verb and resource. Differentiates from sibling 'read_messages' (plural) and 'read_thread' by specifying 'single message'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool vs alternatives like 'read_messages' or 'read_thread'. Does not mention prerequisites, when not to use, or scenarios.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare the tool as read-only and idempotent, but the description adds minimal behavioral detail—it mentions 'recent' without defining recency or ordering, and omits pagination info. The description does not contradict annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is short and to the point, with no wasted words. However, the structure could be improved by separating the purpose from parameter descriptions.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite annotations and an output schema, the description lacks key pipeline details: ordering, pagination, and what 'recent' means. For a list tool, this incomplete guidance may lead agents to misuse or misunderstand the scope.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description should compensate, but it merely restates the schema titles ('The inbox to read from', 'Maximum number of messages to return') without adding value like examples or default behavior nuances.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Read recent messages in an inbox' using a specific verb and resource, and distinguishes from siblings like 'read_message' (single) and 'list_inboxes' (different resource).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like 'read_message' or 'list_threads'. The description lacks context about the intended use case.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the description's mention of 'Read all messages' is consistent but adds no new behavioral context beyond stating it reads a thread. With annotations covering safety and idempotency, the description's contribution is minimal.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences with purpose first, followed by concise parameter list. No redundant information. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Tool is simple (read operation) and has an output schema, so the description does not need to explain return values. It covers required parameters and core purpose. Missing details like ordering or pagination, but acceptable for a straightforward read-all tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries full burden. It adds meaning by stating 'The inbox containing the thread' and 'The thread ID to read,' which explains the role of each parameter beyond the schema titles. However, it does not specify parameter format or constraints (e.g., UUID), leaving some ambiguity.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states 'Read all messages in a conversation thread.' The verb 'read' and resource 'messages in a thread' are specific. It distinguishes from siblings like 'read_message' (single message) and 'list_threads' (list threads without reading messages).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives. It does not mention prerequisites like obtaining inbox_id and thread_id from other tools (e.g., list_threads). No exclusions or when-not-to-use hints.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate it is a write operation (readOnlyHint false) and not destructive. Description adds the behavioral trait of automatic threading header setting, but does not disclose side effects on the original message or permission requirements.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Description is concise with the purpose stated upfront, followed by a useful behavioral note and parameter list. No unnecessary words, but the 'Args:' label is slightly redundant.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers the core functionality and parameters. Missing return value description despite existence of output schema. No mention of error conditions or prerequisites like inbox existence. Adequate but not comprehensive.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% but description adds meaningful explanations for all three parameters: inbox_id (which inbox), message_id (which message), body (plain text). This adds value beyond the schema's title-only definitions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states 'Reply to a message' with a verb and resource. Mentions threading header automation. However, does not differentiate from sibling tool 'forward_message' which could cause confusion.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like 'forward_message' or 'send_email'. No prerequisites or context provided for appropriate use.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate readOnlyHint=false and destructiveHint=false. The description adds context that the body is plain text and that recipients are comma-separated. It does not contradict annotations and provides useful behavioral details beyond the schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and front-loaded with the main purpose. The parameter list is efficient and uses clear formatting. Every sentence adds value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (6 params, output schema exists), the description covers parameters well but lacks context on error handling, authentication, or limitations (e.g., attachments). More guidance would improve completeness.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, but the description compensates by explaining all six parameters: inbox_id, to, subject, body (plain text), cc, bcc (comma-separated). It adds meaning beyond the schema's titles and defaults.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Send an email from an inbox.' It provides a specific verb (send) and resource (email), and distinguishes from siblings like reply_to_message and forward_message by focusing on sending a new email.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage (when you need to send a new email) but lacks explicit guidance on when not to use it or what alternatives exist. No prerequisites or failures are mentioned.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Discloses that the tool blocks until a new email arrives and only returns emails arriving after the call. Annotations agree (readOnlyHint, no destructive). Missing explicit mention of timeout behavior (return null or throw?), but the timeout_seconds parameter and its default are documented, partially covering this.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured with a summary line, usage note, and parameter list. It is concise but not excessively terse; however, the parameter list could be slightly more integrated into the flow.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers all parameters, usage context, and the blocking behavior. With an output schema present, return value details are not needed. Lacks explicit comparison to sibling tools, but the tool's niche is clear.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema has 0% description coverage, but the description's Args section provides clear explanations for all four parameters, including the purpose of from_contains, subject_contains, and the default for timeout_seconds. This fully compensates for the schema gaps.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb phrase 'Block until a NEW inbound email arrives' and clearly identifies the resource (email inbox). It distinguishes from sibling tools like read_message or list_threads by emphasizing the blocking wait for new messages.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly recommends use for signup/verification flows and provides a clear workflow: 'trigger the action that sends the email, then call this to receive it.' It also notes that only emails arriving after the call count. However, it does not mention when not to use or contrast with alternatives like using read_message for existing emails.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.