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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds meaningful behavior beyond that: multi-param 'first match wins' resolution, the fact that it returns the matched platform, and the authentication requirement (free StartupHub.ai account). It is silent on failure/not-found behavior, which keeps this from 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?

Four tight sentences, front-loaded with the core action and followed by input format, resolution rule, return, and auth. Every sentence carries information, though the stacked parentheticals make it slightly dense.

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 correctly states what is returned (full person profile + matched platform). Auth requirements and input flexibility are covered. Only not-found/ambiguity behavior is left unstated for a simple lookup tool.

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 baseline would be 3, but the description adds cross-parameter semantics the schema cannot express: that multiple handles may be supplied and 'first match wins'. This is real added meaning over the per-param 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 a specific verb+resource: 'Reverse-lookup a person profile by any of their social URLs/handles', which is unambiguous and distinct from get_person_by_email. It does not explicitly contrast with the closest sibling, get_investor_by_social, but the 'person' scope is clear from the name and text.

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?

It specifies which params to pass (linkedin, twitter, or github) and that multiple are allowed with first-match semantics, which is useful context. However, it gives no guidance on when to prefer this tool over get_person_by_email or search_people, leaving alternative selection to inference.

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