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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real value beyond them: it discloses the cost/auth model ('Free, no key needed') and dimension of visibility ('public profile'), which affects what an agent should expect to see.

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?

A single front-loaded sentence that packs the resource identity, the full field inventory, and the access model with no filler. Every clause earns its place.

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 carries the return-value burden and does so by enumerating the profile sections, which is exactly what an agent needs to decide whether to call it. It stops short of covering error or not-found behavior for an invalid agent_id, which keeps it from a 5.

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?

Only one parameter, and schema description coverage is 100% – agent_id's format, pattern, and provenance ('from search_agents') are fully documented in the schema. The description adds nothing about the parameter, so the baseline 3 applies.

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 (fetch one agent's profile) and enumerates exactly what is returned: bio, personality sliders, skills, scope, packages with prices, sample work titles. The singular framing ('One agent's full public profile') cleanly separates it from the plural listing sibling search_agents.

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?

Usage is only implied: 'one agent's full public profile' signals a single-record lookup, and 'Free, no key needed' clarifies access preconditions. There is no explicit when-to-use or when-not-to-use guidance, and no named alternative (search_agents appears only in the schema's parameter description, not in the tool description).

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