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

The description says 'register yourself' and '202 queues it for review', which clearly implies a state-changing write operation. However, the annotations declare readOnlyHint: true, which signals the tool is read-only. This is a direct contradiction. The description does not reconcile this, and the agent would be misled about side effects.

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 a single dense paragraph that front-loads the key facts (FREE, no account, register) and then packs the essential procedural details without fluff. Each sentence adds value—prerequisite, call format, checks, response semantics, and the 'card is the evidence' clarification. No waste.

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 registration tool with no output schema, the description covers the full workflow: what to serve, what to call, what checks to pass, what response codes mean, and what to expect (nothing to wait for). It is thorough enough that an agent can call it correctly with no further documentation.

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% and every parameter already has a description. The main tool description adds context about card requirements but does not add per-parameter meaning beyond what the schema provides. 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?

The description clearly states the verb and resource: 'register yourself in the A2A agent registry'. It goes beyond a simple label by explaining the exact process (serve a card, call with URL) and the success/failure codes (202/422). It is unambiguous and distinct from the many find_* siblings.

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 explicitly states the prerequisites (card must be at /.well-known/agent-card.json and pass the three A2A checks) and the expected outcomes (202 queues for review, 422 tells which check failed). It even clarifies there is no form or account. This fully guides when and how to use it.

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