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

Annotations already cover read-only/idempotent/destructive=false, and the description goes well beyond: it documents the exact return shape (presets [{name, count, fields}] plus fields_per_lookup (50)), the reduced shape when preset is supplied, that the call is free, and the specific error code preset_unknown with known presets returned. That is real operational context an agent cannot get from the annotations.

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 purpose, then routes to alternatives, then output, cost and errors in a compact labeled sequence. Dense but zero filler; every sentence (including the sibling-tool division and the output-shape note) carries distinct information.

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?

There is no output schema, yet the description fully specifies the return payload, the single-parameter variant, the absence of cost, and the failure mode. For a one-parameter read-only catalog tool, nothing an agent needs to call it correctly is missing.

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 relational semantics: the value must be an exact preset name drawn from this catalog, and it is the same value accepted as 'preset' by four sibling tools. It does not restate format/case rules beyond 'exact', which keeps it just short of 5.

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+resource ('List the named field bundles (presets)') and immediately grounds it with concrete preset examples (terrain, flood_risk, natural_hazard...). The division-of-catalog-tools paragraph makes it unmistakable against siblings like search_fields and describe_fields.

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 partitions the three catalog tools: list_presets answers 'which bundles exist and what is in them (names only)', search_fields finds by keyword or lists with an empty query, describe_fields returns full metadata for exact names. It also tells the agent where the returned preset names are consumed (fetch_location, fetch_batch, parcel_enrich, start_run).

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