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

Annotations already cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=true); the description adds real behavioral consequence beyond them by stating that shared projects afterwards appear in project_status and become editable via save_project. It omits error handling for invalid or expired codes, but the post-call state change is the key disclosure.

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 with a colon that delivers the action, the precondition, and the resulting state, with no filler. Everything present earns its place.

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 only two well-documented parameters, no output schema, and annotations covering safety and idempotency, the description supplies the needed post-conditions via project_status and save_project. Only failure modes (bad or already-used invite code) are left unaddressed.

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 description coverage is 100%, so both code and request_key are already documented in the schema, including the pinv_ prefix and idempotency semantics. The description only restates that the code comes from a project owner and adds no format or edge-case detail beyond the schema, so 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?

States a specific verb (accept) and resource (a co-editor invite code from a project owner), so the agent can tell this is the redeem side of co-editor sharing. It does not explicitly name the sibling invite_coeditor as the issuing counterpart, so differentiation is inferred rather than stated.

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 condition for use is clear: the human has an invite code from a project owner. The description also tells the agent what becomes available afterward (project_status lists the shared projects, save_project edits them), which implies the follow-on flow without spelling out when-not-to-use or failure cases.

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