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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the core safety profile is covered. The description adds useful behavioral context by stating that the tool returns user profiles with propertiesasi and includes a concrete example showing the expected call shape with the API key.

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 two sentences plus an example, with the main purpose front-loaded and no filler. Each element earns its place: the purpose, the return type, and a realistic invocation example that clarifies parameter usage.

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 simple parameter set, full schema coverage, safety annotations, and the presence of an output schema, the description is nearly complete. The only minor gap is that it does not explicitly state behavior when the optional 'search' parameter is omitted, though the schema example with only project_id and _apiKey implies that it returns all persons.

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 is already documented with its type and purpose. The description adds an example usage but does not explain parameter meaning beyond what the schema provides, which aligns with the baseline of 3 for high schema coverage.

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 uses a specific verb ('Search') and a clear resource ('persons (users) in a PostHog project'), making the tool's function unambiguous. It also states the return value ('user profiles with properties'), which further distinguishes it from sibling tools focused on events or insights.

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 purpose statement implies when to use this tool (when you need to find persons in a PostHog project), but it does not explicitly mention alternatives, exclusions, or conditions such as 'use get_events for event data instead.' Usage guidance is present only by implication.

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