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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower; the description still adds genuine context by defining what 'publication verification' means and explicitly warning that it is not a claim of indexing or current freshness. That caveat about data provenance is exactly the kind of behavioral detail structured fields cannot carry.

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?

Three tight sentences with no filler, led by the returned payload and followed by the scope and provenance caveats. The front-loading is reasonable, though the final sentence about publication verification is dense enough to need a second read.

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?

An output schema exists, so return values need not be described, and the description covers the payload, its scope limits, and provenance caveats. The one meaningful gap is the undocumented area_id parameter, which is partially excused by the low-complexity, read-only nature of the tool.

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?

The single area_id parameter has 0% schema description coverage and only a regex pattern, and the description never mentions it or explains how it scopes the returned coverage. With one undocumented optional parameter and no compensating prose, the description leaves the parameter's meaning to inference.

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 states the resource returned - dataset version, included states, and site-area coverage - which is a specific metadata payload rather than a search, and it distinguishes itself from the search siblings by declaring 'This is the site catalogue, not all United States streets.' It stops short of a crisp verb-first statement of what invoking it does, so a 4 rather than a 5.

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?

Usage is only implied: by framing itself as the catalogue rather than a street search, it hints you consult it to learn what the dataset covers before searching. There is no explicit 'use this when / don't use this when' and no named alternative among search_areas, search_streets, get_street_context, or compare_streets.

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