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

With no annotations provided, the description carries the full burden and does well: it discloses that unsupported resource strings are ignored with warnings, that existing waypoints should be merged rather than duplicated, and that route-only plans should be labeled incomplete. It does not spell out persistence or side effects, but the 'Add to artifact' phrasing implies mutation and the warnings about ignored data are valuable behavioral details.

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 four sentences, front-loaded with the core purpose, and every sentence earns its place by addressing usage, duplicate avoidance, mode preference, and incompleteness labeling. There is no fluff or repetition of schema details.

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?

Given the tool's complexity (nested waypoints object, many enum options, no annotations) the description is quite comprehensive. It covers critical corner cases: existing waypoints, free-text resources, unsupported strings, and route-only plans. It does not mention return value format, but an output schema exists, so that is not required. A few minor gaps remain, such as explicit idempotency or confirmation behavior when official data is absent.

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 only 50%, but the description compensates by adding strategic guidance: prefer waypoints.mode=structured, place non-canonical details in notes/source text, and use table_url with caution ('verify results'). It also clarifies resource handling, which maps to the items.resources enum. This adds meaning beyond the raw schema, though it does not explain every nested field.

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 opens with a specific verb and resource: 'Add structured aid stations, checkpoints, cutoffs, and canonical resources to a CRSProf artifact that lacks them.' This clearly distinguishes the tool from siblings like generate_course_segments or validate_course_profile by focusing on enriching waypoint metadata. The scope is precise and unambiguous.

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 clear when-to-use context: enrich when the artifact lacks waypoints, inspect for existing GPX/CRSProf waypoints first, and avoid duplicates by merging/updating. It also advises preferring waypoints.mode=structured and marking route-only plans as incomplete unless official details exist. It does not explicitly name an alternative tool, but the guidance is strong enough for an agent to decide when to invoke this tool.

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