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

Annotations already cover the read-only/idempotent safety profile, so the bar is lower. The description adds real value beyond them: the entitlement requirement (Creator Max or agency Pro/Scale/Enterprise) and the fact that email is returned only "when it was already revealed," implying a separate reveal step.

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, front-loaded with purpose, then usage hint, then entitlement/return info. Little waste, though the return-field sentence overlaps with the existing output 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?

Covers purpose, key filter, entitlement gate, and returned fields for a 13-param tool whose output schema is already provided. Sufficient for correct invocation, missing only explicit sibling routing.

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% across 13 params, so the schema already documents every parameter. The description only echoes the company_id filtering pattern and adds no syntax or semantics beyond the schema. 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?

States a specific verb (List) and resource (influencer-marketing and creator-partnership professionals) and scopes it to the Find sponsors directory. Clearly distinguished from sibling sponsor_search_brands (brands) and sponsor_get_contact (single contact).

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?

"usually filtered to one brand by company_id" gives an implied usage pattern, but there is no explicit when-to-use vs alternatives (e.g., sponsor_get_contact, sponsor_search_brands, sponsor_reveal_email) or when-not guidance. Adequate but with clear gaps.

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