build_check_prerequisite

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states it's a 'check', which implies read-only, but does not explicitly confirm it has no side effects, doesn't modify the character, or what kind of result it returns. It lacks any detail on error behavior, auth, or rate limits, leaving much unsaid.

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 description is a single sentence, front-loaded with the core action and usage context. Every word earns its place, and it avoids redundancy or filler, making it highly concise and well-structured.

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?

The description is adequate for a narrow, simple tool: it states the purpose and when to use it. However, it lacks details on input expectations (e.g., what the character object needs) and does not disclose any behavioral nuances. The presence of an output schema reduces the need to describe return values, but the overall information is still minimal.

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 0%, so the description must compensate. It only mentions 'single-feat' and 'one user-proposed choice', which vaguely maps to feat_id, but gives no guidance on the 'character' object structure or the format of feat_id. The schema shows character is an open object with additionalProperties, but the description does not clarify required fields or expected shape.

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?

The description clearly states the tool performs a 'narrow single-feat eligibility check', identifying the action (eligibility check) and resource (a single feat). It distinguishes from siblings by contrasting with 'full discovery', so its purpose is specific and not easily confused with broader build tools.

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 description explicitly says 'use when sanity-checking one user-proposed choice rather than re-running full discovery', providing clear context of when to use it. It implies a lightweight, targeted scenario and distinguishes from heavier alternatives, though it doesn't enumerate specific sibling tools.

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