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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds valuable behavioral content beyond that: it discloses the concrete outputs (minimum distance, error-correction guarantee, distance matrices, optional pruned subset), which is what the agent needs to know about the result.

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 the key distinction (audit existing vs design new) before enumerating outputs. The em-dash chain is slightly dense and the closing sentence is somewhat decorative, but 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 an output schema present, return values needn't be spelled out, and annotations carry the safety profile. The description covers purpose, alternative, and the audit computations; it is complete enough for correct selection and invocation.

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 the schema already documents metric, prune_to_errors, required_distance and the record params. The description gestures at pruning ('subset that survives pruning to a stricter error budget') but adds no syntax or format detail beyond the schema, so 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 (check/audit) and resource (an index set you already have), and explicitly separates itself from the design-a-new-one path. An agent can distinguish this from design_barcodes/design_free_codes without opening the 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?

Explicitly frames the use case: 'Check an index set you ALREADY have, rather than designing a new one,' and gives the scenario ('inherited from a kit or a previous experiment'). It names the alternative category rather than a specific sibling tool, so a 4 rather than 5.

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