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

Annotations only declare the mutation profile (readOnly=false, idempotent=false, destructive=false); the description goes well beyond by stating the shareable link is stable and every earlier version is preserved with revert_to (so removals are recoverable despite the destructive flag being false). It also discloses that live_hazards are a snapshot frozen at render time and must be re-made to refresh, and that flood zones come from FEMA/Environment Agency and House districts use Missouri 2022 lines.

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 create-vs-edit distinction, and the trailing sentences on link stability and get_map discovery are high-value. However the long semicolon chain of capabilities is dense and hard to scan, with no grouping of the change types beyond punctuation.

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 an 11-parameter nested mutation tool with no output schema, the description covers the operation surface, versioning behaviour, discovery step via get_map, and refresh semantics for live hazards. Remaining gaps are minor: the 'legend' boolean and the exact requirement for layer creation on add_layers are left to the schema.

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?

With 64% schema coverage across 11 params, the description meaningfully supplements the schema by explaining the pin-identification model (by id, with lat/lng or an address), the three recolour modes (single colour, by field values with per-value colours, or numeric bins in the user's own bands), and the upsert semantics of adding vs. moving pins. It leaves some params thin — notably 'legend' and 'revert_to' are not elaborated beyond the schema.

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 precise verb+resource pair ('Change a map made with render_map') and then enumerates the concrete operation classes: add/remove layers, move/rename/add/remove pins, recolour, show/hide, rename, draw flood zones or House districts. An agent can distinguish this from render_map (creation) and delete_map without opening 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?

It establishes the use case as editing an existing map rather than creating one, points to render_map as the source, and tells the agent to call get_map to discover layer names, pin ids and fields before issuing changes — a genuine prerequisite. It also routes version restoration to revert_to rather than a separate tool. No explicit 'do not use this for X' exclusion, which keeps it short of a 5.

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