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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds substantial non-obvious behavior: the per-30-day unstar budget consumption, the free-trim exception when over the star cap, and the anti-cycling rationale. It also points to get_account for the remaining budget, which is real operational context not present in any structured field.

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 the core action and a WARNING before the rationale and edge-case policy. Five sentences is on the long side for a single-parameter mutation, but each sentence carries a distinct behavioral rule, so little 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?

For a single-param mutation with no output schema, the description covers action, cost model, exception, and policy constraints. An agent has everything needed to decide whether to call it and what to warn the user about.

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?

Only one parameter and schema coverage is 100%, so the schema fully documents listingId. The description adds no syntax or format detail beyond what the schema already provides; 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 and resource ('Remove a star from a company listing'), and the sibling set contains star_listing, whose inverse this clearly is. It stops short of explicitly naming star_listing as the counterpart, so the differentiation is inferable 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?

Gives explicit when-to-use ('Only unstar if the company is truly not relevant'), explicit when-not ('Do NOT mass-unstar to get a user under their cap unless they explicitly ask'), and prescribes an alternative behavior (surface the choice, let the user decide). This is about as complete as usage guidance gets.

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