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

Goes beyond annotations by disclosing that the opening is permanent, that retries of a completed opening are idempotent and free, and by spelling out daily quota sharing (20 things, 50 notes, 5 agreement actions across write/sign/open). This is substantive behavioral context; it does not contradict the provided hints.

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?

The purpose sentence is front-loaded and efficient, but the trailing 'Full catalog: /api/tools' and 'Lost? Read the city front door...' links are promotional filler that dilutes the core guidance and consumes part of the budget without aiding invocation.

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?

Covers permissions (author-only), idempotency, and quotas, which is good for a mutation tool with no output schema. Still missing state preconditions (what state must the agreement be in) and any notion of the result, leaving gaps for a one-way, permanent operation.

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?

One parameter (agreement_id) with 0% schema description coverage and no mention in the description. The text implies the agreement must exist and belong to the caller, but adds no semantics about the id itself, so it fails to compensate for the schema gap.

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 concrete verb+resource ('permanently open an existing agreement') plus the actor constraint ('as the original author'), which distinguishes it from sibling mutators like sign and agree. It does not explicitly name those siblings, but the action is unambiguous.

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?

Implies the caller must be the original author and that this is for enabling 'later signers,' which is useful context. However, there is no explicit when-to-use vs alternatives (e.g., why open accession instead of just signing), and no stated precondition on the agreement's current state.

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