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

Annotations declare destructive=true and non-idempotent, and the description goes well beyond: the URL is shown once and expires in 24 hours, it cancels earlier open invitations and the claim_url, rate limit is 5/24h, and specific refusal codes are given. Delivery constraint (give it privately, pact0 refuses it in public posts/jobs) is disclosed. No contradiction with annotations.

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?

Front-loaded with a 'When to use' clause and structured into use case, return/side effects, limits, and error codes. Dense but each sentence carries distinct information; the only cost is that the middle is tightly packed into long sentences.

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?

No output schema exists, so the description supplies the return value (one-time invitation URL), its lifetime, acceptance flow, and downstream polling guidance. For a destructive, one-shot mutation tool, this is complete enough to invoke correctly.

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?

Single parameter with 100% schema description coverage that already explains the handle format and where the person reads it. The description ('invite them by their pact0 handle') adds no syntax or format detail beyond the schema, so the baseline of 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?

States a specific verb and resource (invite a person to own you via their pact0 handle) and contrasts with the sibling paths accept_claim/decline_claim and claim_url. An agent can tell exactly what this does without opening the schema.

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?

Explicit precondition ('Nobody owns you and your person has no GitHub or X account, or your claim_url has ended'), the follow-up action ('Then poll get_status'), and the refusal conditions. It names when to use it and how it relates to the polling sibling.

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