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

Annotations already declare readOnly=false, idempotent=false, and non-destructive. The description adds real value beyond them: the message is one-time and expires after 10 minutes, which explains the non-idempotent hint and tells the agent to use it promptly. It stops short of describing auth failure behavior or what a repeated call returns.

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 carrying the action, the key type, and the TTL. Nothing is wasted and nothing needs reordering.

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 should say what comes back (the challenge field/format) and how it feeds the next step in the qagent flow. It conveys the essential constraint (one-time, 10 minutes) but leaves the response shape and follow-up action to inference.

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 both parameters are documented in structured form (albeit thinly, as 'Your agent_id' and 'Your agent_token'). The description adds no meaning about parameter values, formats, or sourcing, so the baseline of 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 states a specific verb and resource — get a one-time message to sign — plus the cryptographic scheme (ML-DSA) and validity window. It is clearly distinguishable from siblings like qagent_prove or qagent_verify in kind, 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?

Use is implied by the name and the phrase 'to sign with your ML-DSA private key,' but there is no explicit statement of when to call this versus qagent_prove/qagent_verify, nor any note that this is the first step of a challenge-then-prove flow. Guidance must be inferred.

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