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

Annotations already mark readOnly/idempotent/non-destructive, lowering the burden; the description adds meaningful behavior beyond that: a point outside hosted coverage returns an honest 404 with the coverage list rather than a guess, and representative_point is chosen from the largest-area member to avoid off-pacel geometric centers. These details materially affect how the agent interprets results and failure modes.

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?

Extremely dense and front-loaded, with no fluff sentences; the core action and scoping come first. However, it is one long paragraph with heavy parentheticals, and a short bulleted structure would improve scanability for an agent.

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?

Output schema exists, so return-value format doesn't need to be restated; the description adds coverage rollout, 404 error behavior, anchor semantics, handoff integration, and sibling routing. For a 7-param, 0-required tool with two invocation modes, nothing critical 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?

Input schema covers all 7 parameters at 100%, so baseline is 3; the description still adds useful nuance by clarifying that a MultiPolygon 'carries discontinuous pacels as one envelope', that lat/lon is the hosted-lookup path when geometry is omitted, and that capacity_mw passes into the site_evaluation_handoff. It doesn't add substantial syntax detail beyond the schema, but the mode-level semantics are helpful.

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?

Opens with 'Structured read of a parcel BOUNDARY', naming a specific verb (read), resource (parcel boundary), and outcome (anchor + size). It explicitly contrasts with analyze_site and get_refined_queue, so an agent can tell it apart from the closest siblings without digging into schemas.

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?

Provides explicit routing rules: 'Use when you HAVE a boundary or a point on a specific parcel' and directs to analyze_site for general lat/lon site scores and get_refined_queue for queue survivors. It also distinguishes the two input modes — own GeoJSON boundary vs lat/lon hosted-pacel lookup — so usage is unambiguous.

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