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

Beyond the annotations (readOnlyHint, idempotentHint, non-destructive), the description adds critical behavioral details: pagination limits (default 25, max 100, page depth 20), result fields (domain, name, industry, etc.), and account-dependent restrictions (unlinked accounts limited to 90 days, first page, max 25 results). This comprehensively informs the agent of what to expect.

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 efficiently front-loaded with the core purpose, then covers filters, pagination, result fields, account limitations, and sibling pointers in a logical flow. Every sentence adds distinct value, with no redundant or vague statements. It is appropriately sized for the tool's complexity.

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 (9 optional parameters, pagination, account tiers, sibling tools), the description is remarkably complete. It covers filter semantics, pagination caps, result shape, unlinked-account restrictions (90-day window, first page, 25 max), and explicitly references sibling tools for related tasks. The output schema exists, so return-value details are not needed.

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?

All 9 parameters are well-documented in the schema, so schema coverage is 100%, baselining at 3. The description adds value by clarifying the interaction ('All filters are optional and combine (AND)'), explaining that 'category' expects a slug (guiding to list_categories), and that 'industry' is loosely matched free text. This context aids correct usage beyond the schema's individual 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?

The description clearly states the tool's purpose: 'Search companies that sponsor podcasts.' It distinguishes from sibling tools like get_sponsor and list_sponsor_contacts by specifying what each handles. The description also details result fields and pagination, ensuring the agent knows exactly what this tool does versus alternatives.

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 provides explicit guidance on when to use this tool versus alternatives: 'For one company's full profile use get_sponsor; for its buyer-contact list use list_sponsor_contacts.' It also explains filter combination ('All filters are optional and combine (AND)'), pagination limits (page depth capped at 20), and account-specific behavior (linked vs unlinked). This gives the agent clear decision criteria.

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