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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered structurally; the description reinforces it by stating agents cannot create or edit heatmaps and explaining how heatmaps come into existence (SDK registration plus Data page management). It adds provenance and id semantics but says nothing about result size, pagination, or ordering, which is what an agent still lacks for a list call with no output schema.

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 resource definition, then the disambiguation, then the constraint, then the prerequisite — a sensible priority order with no filler. The first sentence is long and packs definitional detail into stacked clauses, which costs a little immediate scannability.

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 documented parameters and no output schema, the description covers what the objects are, why the id matters for downstream query tools, and what an agent cannot do. The remaining gap is return-shape expectations such as pagination or ordering, which matters here because no output schema is present to answer it.

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 coverage is 100%, so the baseline is 3, but the description adds conceptual meaning the schema does not: it explains that the heatmap id is the value a heatmap query's heatmapId points at, which tells an agent why heatmapId filtering exists and how to chain into run_heatmap_query. The search and environment parameters are left entirely to their schema descriptions.

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 (list the project's heatmaps) and then defines the resource itself as map definitions with bounds, resolution and background image, so an agent knows exactly what object class it is enumerating. Crucially it disambiguates from the similarly named heatmap-query siblings by declaring 'A heatmap is not a query' and explaining that its id is the target of a query's heatmapId.

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?

Names the alternatives explicitly (run_heatmap_query, create_heatmap_query) and the relationship that routes between them, states a hard exclusion ('Agents cannot create or edit heatmaps'), and gives an ordering prerequisite ('Load the heatmap-queries skill first'). This is the full when/when-not/alternatives pattern.

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