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

Annotations already declare the safe, idempotent, non-destructive read profile, yet the description still adds value beyond them: a 25-per-page pagination contract, the plan/entitlement required to call it, and the company_id field returned. It does not mention rate limits or behavior on empty results, keeping it short of a 5.

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 tight sentences: purpose first, then output shape and pagination, then the access requirement. Nothing is redundant with the title or schema, and the routing-relevant output field is 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?

With an output schema present, return values need not be explained; the description covers the remaining gaps an agent needs — page size, entitlement requirement, and the downstream chaining field. Complete for a 9-parameter search tool with full schema coverage.

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 every parameter is already documented in the schema; the description only restates the filter dimensions and the page size. Per the baseline rule, a 3 is appropriate when the schema carries the parameter documentation.

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 ("Search the Find sponsors directory for brands") plus the matching dimensions (niche, industry, country, company size). It is easily distinguishable from sibling read tools, but it never contrasts itself with the closely related sponsor_lookup_brand, leaving that differentiation to inference.

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 concrete prerequisites ("Requires Creator Max or an agency Pro, Scale, or Enterprise plan") and a workflow cue (company_id feeds sponsor_search_contacts and sponsor_get_brand). It stops short of stating when to prefer this over sponsor_lookup_brand, so no explicit alternatives or exclusions are given.

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