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

Annotations already cover the mutation profile (not read-only, idempotent, non-destructive). The description adds real context beyond them: the Web Bot Auth headers (Signature, Signature-Input, Signature-Agent) must accompany the call, and the outcome is a Verified agent badge. It says nothing about whether re-declaring overwrites prior operator data or how long verification takes.

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?

Three tight sentences with the purpose front-loaded, then the prerequisite, then the reward, then a reference link. The opening fragment 'Optional Agent ID:' is slightly awkward but costs little.

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 an idempotent write tool with no output schema, the description covers the prerequisite headers and the payoff, plus an external doc link. It omits what a successful response looks like and whether the declaration can be updated later, which an agent would want before calling.

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 each field carries an example, so the baseline is 3. The description only echoes the field list without adding format or constraint detail beyond what the schema already states.

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?

'Declare who runs you' is a specific verb+resource, and the parenthetical enumerates the exact fields declared. It is distinguishable from register_agent only by inference ('Optional Agent ID' implies registration already happened), so it stops short of a 5.

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 word 'Optional' signals this call is not mandatory and the badge sentence implies a reason to use it, but there is no explicit when/when-not or mention of the sibling register_agent that an agent must already have completed.

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