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

Annotations already provide readOnly/idempotent/non-destructive hints, so the bar is lower; the description adds domain-specific transparency: it is a read-only lookup that does not register, transfer, or change DNS, and it explicitly warns there is no composite appraisal score—only flags and per-section detail. This sets output expectations beyond the structured 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?

Three sentences are used efficiently: the first front-loads what the tool is and what it returns, the second gives the use case, and the third handles exclusions and caveats. There is no filler or repetition of schema 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?

With no output schema, the description carries the burden of describing the response shape, and it does so by listing the report sections and clarifying that output is flags and per-section detail only. It also covers input scope, safety, and sibling routing, making it complete for an agent to invoke 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 schema already covers the single domain parameter at 100% with an example. The description adds meaning by framing it as 'one known domain' and 'a specific name,' signaling that the value must be an exact existing domain rather than a pattern or search term.

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 verb-object pair—'Due-diligence report for one known domain'—and enumerates the concrete report sections (RDAP, backlinks, authority, toxic-linker flags, Wayback, trademark links). It also explicitly distinguishes itself from siblings by stating it is not for generating names or listing pattern matches.

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 states exactly when to use it ('before buying a specific name') and gives explicit negative conditions with named alternatives: do not use to generate names (find_available_domains) or list pattern matches (find_available_domains_by_pattern). This leaves no ambiguity about routing.

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 cover read-only, open-world, idempotent, and non-destructive traits. The description adds genuinely useful behavioral context beyond those: live verification against RDAP, availability can change before purchase, daily rate limit, and no registration/transfer side effects. This significantly helps an agent set expectations.

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 compact and front-loaded: it states the core behavior first, then usage routing, safety, and operational caveats. Every sentence adds value, and no content is duplicated from the schema or annotations.

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 that the schema already covers all parameters and annotations cover the safety profile, the description provides the remaining operational context an agent needs: live registry verification, availability caveat, rate limiting, and sibling-tool routing. No critical calling information 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 description coverage is 100%, so each parameter already has a meaningful description in the schema. The tool description reinforces the business-idea context but does not add new parameter-level semantics beyond what the input schema provides. Thus the baseline 3 is appropriate.

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 verb and resource: generate brandable .com name ideas and return only currently available names verified against the Verisign RDAP registry. It clearly distinguishes itself from the sibling tools by noting it is not for single-domain checks or exhaustive pattern scans.

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 says when to use it ('when the user wants name ideas they can actually buy') and when not to, naming both alternatives: check_domain for a single known domain and find_available_domains_by_pattern for exhaustive starts/ends/contains scans. This leaves little room for an agent to route incorrectly.

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. The description adds useful behavioral context beyond that: every candidate is 'verified live against the registry,' taken names are omitted, and the tool 'does not register domains.' It also notes default TLDs. This is strong supplemental transparency, though it does not discuss timing or potential 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?

The description is dense and front-loaded: it states the core behavior first, then usage guidance, then behavioral caveats. Every sentence earns its place, and there is no repetition of schema content. Despite its length, it remains tightly organized and easy to parse.

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 read-only enumeration tool with four well-documented parameters and rich annotations, the description is complete. It covers what the tool returns (available domains), how results are verified, default scope, exclusions, and safety. The lack of an output schema is acceptable because the description clearly frames the return as a list of available matching domains.

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 the baseline is 3. The description reinforces meaning by explaining the pattern positions and default TLDs, but it does not add substantive parameter detail beyond what the schema already provides. This is acceptable because the schema fully documents each parameter.

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 verb and resource: 'Enumerate every currently available domain matching a keyword pattern' across selected TLDs. It names the exact pattern types (starts-with, ends-with, contains, or all) and explicitly differentiates itself from siblings by stating what it is not: not for invented brandables and not for inspecting one known domain.

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 explicit when-to-use guidance: 'Use this when the user already has a keyword and wants an exhaustive list.' It also provides direct exclusions with named alternatives: 'Do not use to brainstorm creative names (use find_available_domains) or to inspect one known domain (use check_domain).' This leaves no ambiguity about tool selection.

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