lookup_runtime_resource

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

The annotation already marks the tool as read-only, idempotent, and non-destructive, and the description adds meaningful behavioral context beyond that: it requires an exact build match and explicitly warns that snapshot content is external data, not instructions. This is a valuable guardrail for an AI agent. It does not describe output or error behavior, but the annotations cover the safety profile.

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 three sentences and every sentence earns its place: purpose, key constraint, and important safety note. It is front-loaded with the primary action and resource, and there is no redundant or filler content.

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 covers the core purpose, prerequisites, locale behavior, and a security-relevant warning. However, with no output schema, it does not explain what the returned data looks like, nor does it describe failure conditions such as when an exact build match is not found. For a lookup tool with five parameters, it is adequate but not fully 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?

Schema description coverage is low at 40%, so the description must compensate, and it largely does. It clarifies what each 'kind' corresponds to, explains that locale is relevant only to localized values, and ties the exact-build-match requirement to version/channel selection. It does not add much beyond the schema for 'name,' but the main parameters are given meaning.

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 uses a specific verb ('Read') and identifies the resource: explicitly collected local CVar default/flags, atlas geometry, symbol type, or localized string. The kinds are enumerated and match the schema's 'kind' enum, making the tool's scope clear. However, it does not explicitly differentiate this from the sibling 'lookup_resource' tool beyond the word 'local,' so it lacks strong sibling distinction.

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 provides useful usage context: an exact build match is required, and locale can constrain localized values. It does not, however, give explicit when-to-use versus when-not-to-use guidance relative to the many sibling lookup/search tools, nor does it mention alternatives or exclusions.

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