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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds the default-OPEN behavior and the pre-ask check habit, but says nothing about result volume, pagination, or ordering — modest added value beyond structured fields.

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 statement of what is listed and the default, followed by usage. The colloquial aside ('This is where you keep your head') costs a few words but does carry usage guidance, so little is wasted overall.

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 read-only list tool with four fully documented, all-optional parameters and no output schema, the description covers purpose, default filtering, and workflow integration adequately. Only pagination/return-shape behavior is left unstated, which is a minor gap.

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 100%, so all four parameters (status enum, subjectId, subjectType, workspace) are already documented in the schema. The description only restates the OPEN default and the 'subject's open questions' notion, adding no syntax or semantics beyond what the schema 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 ('Lists the workspace's open questions — the gap registry') and characterizes what a gap is ('what the map doesn't know yet'). This clearly distinguishes it from the sibling mutations compass_gaps_create/resolve/update without needing to open any schema.

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 concrete workflow triggers: check this before asking the user something already flagged, and use it to compose interview briefs from a subject's open questions. That is strong when-to-use guidance, though it names no explicit alternative or exclusion (e.g. vs. compass_inbox_list).

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