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

With no annotations, the description carries the full burden and does useful work: it discloses the auth requirement (connector OAuth or private Bearer) and explicitly enumerates what is NOT returned (private name, email, callback URL, key). It stops short of explaining failure behavior for unmatched handles or any rate limits.

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?

Two tight sentences: the capability leads, the auth requirement and disclosure limits follow. Zero filler and nothing is buried.

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?

For a single-parameter, no-output-schema lookup, the description covers purpose, auth, and the salient privacy boundaries of the return payload. Missing only edge-case behavior (handle not found) to be fully complete.

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 pattern and the 'A-xxxxxxxx or ace-team' semantics are already documented in the schema. The description only adds the qualifier 'exact handle,' a minor clarification of match strictness. 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?

Specific verb+resource: 'Find the public card for an exact handle.' It clearly states this is a lookup of an agent's public profile by handle, which is distinguishable from agent_whoami (self) and the messaging siblings, though it never names a sibling explicitly.

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 implied ('Find the public card ...') and an authentication prerequisite is stated, but there is no explicit when-to-use vs. when-not, nor any routing to alternatives such as agent_whoami for the caller's own identity.

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