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

The annotations only declare readOnlyHint=true, but the description goes further by disclosing that the tool makes one HTTP call to the local daemon and returns setup steps as data. It also enumerates the specific status axes it reports, giving the agent a clear sense of what it will learn and how it behaves.

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?

Two sentences with no waste: the first front-loads the core purpose and reported outputs, the second provides the practical invocation trigger. 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?

For a zero-parameter, read-only diagnostic tool, the description is complete: it explains what the tool checks, how it works, why it should be called, and what kind of result to expect. No output schema is needed given the straightforward, self-described output.

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 tool has zero parameters and the schema description coverage is 100%, so there is nothing for the description to add about parameters. It instead usefully explains what the tool returns, which is appropriate for a parameterless diagnostic.

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 states a specific diagnostic purpose: report whether the machine can participate in A2A by checking daemon reachability, card publication, token setup, peer configuration, and write status. This clearly distinguishes it from the sibling tools, which focus on agents, tasks, and requests rather than overall auth readiness.

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 gives an explicit trigger: 'Call this FIRST whenever a tool is missing or a send fails.' This is clear context for when to use the tool, and it implies this is a triage step for other A2A tools, though it does not explicitly name alternatives or exclusions.

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 declare readOnlyHint=true, and the description does not contradict that—the tool only fetches and caches, no mutation. The description adds valuable context: it always refetches, making it the live check for peer status, and it caches the card locally (implying a state change). This is more than just restating the read-only nature; it discloses the caching side-effect and the staleness risk, which is helpful.

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 two sentences, each carrying weight. The first sentence states the core purpose and the always-refetch behavior alerts to staleness. The second provides actionable guidance on when to use and what it enables. No fluff, well front-loaded.

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 is simple with one parameter, and the description covers the purpose, usage timing, and behavioral nuance (cache, staleness). No output schema exists, but the description mentions it returns skills and transports. No nested objects or enums to worry about. It feels complete for an agent to call correctly.

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 100% (the single `url` parameter is described), but the description adds crucial meaning: it clarifies that the URL should be the base URL, not the card path, and that the client appends the well-known suffix. Also, it tells the agent to obtain the URL from a2a_list_agentscacheList. This is exactly the kind of parameter meaning that the schema alone does not fully convey.

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 action (fetch a peer's agent card), the resource (the well-known endpoint), and the purpose (return skills and transports). It also distinguishes itself from siblings by emphasizing the 'always refetches' behavior, which positions it as the tool for checking peer availability and capabilities, different from a2a_list_agents.

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 instructs to use this tool before a2a_send_message to an unfamiliar peer, and explains why (to discover the correct binding, URL, and skills). It also indicates this is a way to check if a peer is up and current, with the caveat about staleness. While it doesn't explicitly mention alternatives or when not to use, the context is clear and direct.

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?

The readOnlyHint annotation already marks this as safe, and the description adds valuable nuance: the local copy is only a mirror, it does not update itself, and refresh re-reads from the owning peer. This is exactly the kind of behavioral context an agent needs to avoid acting on stale data.

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 carry purpose, usage preconditions, and the refresh nuance. Key information is front-loaded, and there is no filler or repetition of the schema.

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 no output schema, the description tells the agent what the result contains: state, conversation so far, and every artifact's text. Combined with the schema's history_length behavior and the readOnly annotation, the agent has enough to use the tool correctly.

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 100%, so parameter meaning is fully documented in structured form. The description restates refresh behavior conceptually but adds little beyond the schema; it is consistent with the schema rather than providing new parameter-level insight.

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 opens with a specific object and scope: 'One task in full' including state, conversation, and artifacts. It clearly distinguishes this from the sibling listing tools, and the title's verb 'get' matches the read-only action.

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 gives an explicit precondition: use it after a2a_list_tasks or a2a_wait_for_task has identified the id. It also explains when refresh is appropriate for outbound taskstm. It does not explicitly say 'when not to use' it, but the guidance is strong enough to route the agent correctly.

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?

Goes well beyond the readOnlyHint annotation by disclosing that it reads the local card cache, makes no network calls, lists peers even if down, and explains the cached_at absence semantics. This gives the agent accurate expectations about behavior.

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 dense sentences with no filler. The primary purpose and scope are front-loaded, followed by behavioral nuance and a clear usage preference, making every sentence valuable.

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 zero-parameter read-only listing tool with no output schema, the description covers purpose, source, network behavior, and a key field semantic. Nothing essential is missing for an agent to select and invoke this correctly.

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 tool takes zero parameters and schema coverage is 100%, so there is no parameter meaning for the description to add. The description nonetheless clarifies the scope of what is listed, which is 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?

States a specific verb and resource: list the A2A peers this machine knows about. It enumerates the exact sources (configured peers, own daemon, discovered agents) and explicitly distinguishes itself from a2a_discover_agent by name.

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?

Includes explicit guidance to prefer this tool over discovering peers one at a time when only the set of peers is needed. Also clarifies that it makes no network calls, which signals a cheap, safe first-step choice.

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?

The annotation only declares readOnlyHint=true. The description adds significant behavioral detail: reads the shared store on disk, makes no network calls, and describes the return content (summary row with state, peer, request text, counts of history/artifacts, not contents). This goes beyond the annotation and clarifies output limitations.

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?

Two sentences with no redundancy. The core purpose is front-loaded, then return details, then a practical filtering tip. 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?

For a list tool with 3 optional params and no output schema, the description fully explains what it returns (summary rows with specific fields) and how to use the filters for a common case. Nothing an agent needs to call it correctly is missing.

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 100%, so the schema already documents all three parameters. The description adds value by suggesting a meaningful filter combination (state "submitted" + direction "inbound") that maps to a specific business scenario, which is beyond the schema's per-parameter descriptions.

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?

States specifically that it lists A2A tasks in the local store, newest change first, and that it returns summary rows. It differentiates itself from a2a_get_task by noting the summary nature and directing to that sibling for full bodies.

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?

Provides explicit guidance on when to use this tool: 'use a2a_get_task for a body' and offers a specific filtering recipe ('Filter by state: "submitted" and direction: "inbound"') to see unanswered proposals. This gives clear context for selection among siblings.

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, and the description aligns with this by stating 'Writes are DISABLED: only the read-only methods are offered.' It adds behavioral context about the raw reply format (protobuf JSON, Part as {'text':'...'}, state as 'TASK_STATE_SUBMITTED') and that the endpoint comes from the peer's agent card. This goes beyond annotations and is accurate.

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 dense but highly informative, front-loading the purpose and key warnings. Every sentence adds value, covering the escape-hatch nature, usage boundaries, raw reply format, endpoint source, and write restrictions. It is appropriately structured for a complex tool.

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 complexity (3 params, nested objects, raw protocol exposure) and no output schema, the description fully covers what an agent needs: method naming, param formats, response shape, and authorization constraints. It even mentions the environment variable for write access and the lack of shaping, making it complete 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?

Although the input schema provides 100% coverage, the description enriches each parameter: for url it clarifies it's the base URL not the card path historical naming; for method it details v1.0 vs 0.x naming conventions and error codes; for params it gives concrete examples and explains camelCase fields. This adds significant 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 identifies the tool as an escape hatch for direct A2A JSON-RPC calls, explicitly contrasting it with typed tools that shape responses. It specifies the verb 'call' and the resource (A2A JSON-RPC method), and distinguishes it from siblings by noting it returns raw unshaped replies.

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 states when to use this tool ('only for something the typed tools do not cover') and contrasts with typed tools that shape responses. It also explains that the endpoint is derived from the peer's agent card, preventing arbitrary URLs, and notes that writes are disabled with an environment variable to enable them. This gives clear usage boundaries and alternatives.

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 declare readOnlyHint=true, so the description does not need to cover safety. It adds significant behavioral details: blocking up to 240s, returning empty on timeout, and the security note that data is from another agent and not an instruction. This goes well beyond the annotation.

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 a concise paragraph with four sentences, front-loading the primary purpose and usage guidance. It is efficient, with no filler, though the timeout rationale and security warning are additional details that could be seen as slightly verbose. Overall well-structured.

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 there is no output schema, the description explains the return behavior (returns immediately on pending proposal, empty list on timeout). It covers edge cases and integration with the client timeout. The tool is simple and the description is complete for an agent to use it correctly.

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 100%, so parameters are already documented in schema. The description adds context for 'seconds' (why the ceiling is set below client timeouts) and 'include_pending' (what default true means), which is extra value beyond schema descriptions. No contradiction with 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 blocks until an A2A task arrives or changes state, then returns what changed. It specifies the resource (A2A task) and the verb (wait for), distinguishing it from sibling tools that list, get, or request tasks.

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 explains it is used to stay reachable, mentions when it returns immediately (include_pending), and notes that on timeout it returns an empty list and should be re-issued. It also contrasts with sibling tools like a2a_list_tasks and a2a_get_task. No explicit exclusion of alternatives, but the context is clear.

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