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

Adds real context beyond the annotations: 'Writes nothing anywhere' reinforces readOnlyHint, 'Early access' flags availability, and the auth/scope requirement plus the 403 failure mode on unclaimed workspaces are operational facts the agent cannot get from structured fields. Also clarifies the delivery mechanism (files + git-applicable patch) rather than mutating a repo.

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-loads what is generated and what it produces, then prerequisites. The clipped, telegraphic phrasing ('Writes nothing anywhere. Early access. Needs...') is efficient but slightly staccato; no sentence is wasted.

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 still tells the agent what it gets back (source files plus one patch for git apply) and what it must have before calling. Coverage of how the generated code is parameterized is thin, but the essential call-time requirements are present.

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 80%, so the schema already documents agent_id, payments, customers and event_name. The description only loosely echoes them ('Next.js, Express or FastAPI' maps to the framework enum; 'creates customers' and 'bills through Stripe' hint at the toggles) without explaining defaults or the event_name pattern, so it adds little beyond the schema.

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 artifact: writes Last Price integration code for Next.js/Express/FastAPI, including a client that records signals, prices calls, creates customers and bills via Stripe, delivered as files plus a git patch. The output shape ('files and one patch for git apply') plus 'Writes nothing anywhere' cleanly separates it from sibling `open_monetization_pull_request`.

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?

Gives clear preconditions: a Last Price credential with billing read scope and a claimed workspace, and warns that a self-registration sandbox key is refused with 403 until a person claims it. It does not explicitly name a contrasting sibling or say when to prefer it over opening a PR, so the routing is inferable rather than stated.

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