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

No annotations are supplied, so the description carries the full burden. It does add real behavioral context by disclosing the consequence of accepting (the caller gains the ability to approve/reject pending actions for that account), but it says nothing about whether acceptance is reversible, whether revocation is required to undo it, or what the response contains.

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?

Two short sentences, zero waste, with the action front-loaded and the consequence second. Nothing gratuitous and nothing buried.

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 one-parameter tool with no output schema and no annotations, the definition covers what the action is and what it enables. A slightly fuller account of edge cases (invite expired, already a co-signer) would make it complete.

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?

The single parameter has 100% schema description coverage and the schema itself explains where the value comes from ("Invite id from list_incoming_cosigner_invites"). The description adds no meaning beyond that, so baseline 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 ("Accept a pending co-signer invite"), so the agent knows exactly what the call does and would not confuse it with list_incoming_cosigner_invites, revoke_cosigner_invite, or invite_cosigner. It stops short of naming those siblings, which keeps it below 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?

Usage is only implied: it says "pending" invite and the effect of accepting, from which the agent infers this is the follow-up to listing incoming invites. There is no explicit when-to-use, when-not-to-use, or handling of already-accepted/expired invites, so guidance remains minimal.

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