Save Site

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

Annotations only say readOnlyHint=false, destructiveHint=false, idempotentHint=false. The description adds substantial behavioral context beyond that: keyless calls return auth_required, the call WRITES to the account, it 'Builds a persistent shortlist an agent can revisit + monitor', and passing market triggers a DCPI baseline snapshot that changes later list_saved_sites/get_changes output. No contradiction with annotations — readOnlyHint=false aligns with the stated write behavior.

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?

Although long, every sentence earns its place: auth warning is front-loaded, followed by function, parameters, return value, side effect, follow-up workflow, exclusions, and a runnable example. The structure is logical and dense with no filler or tautology, appropriate for a tool with 10 parameters and an auth flow.

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?

Given the tool's complexity — account writes, auth requirements, DCPI side effects, and a 10-parameter surface — nothing material is missing. The description covers the auth prerequisite, return value (saved site id), the persistent-shortlist behavior, the alert follow-up, sibling alternatives, and an executable example. An output schema exists to document return details further.

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. The description adds value beyond the schema by clarifying that lat + lon are the operative inputs despite zero required params, explaining market's side-effect behavior ('DC Hub snapshots the site's DCPI baseline at save time'), and providing a concrete example mapping values to parameters. This pushes it above baseline, though the schema already documents the aliases well.

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 names a specific verb + resource + destination: 'Save a candidate data-center site to your DC Hub account to track it across sessions.' It explicitly differentiates itself from the confusable siblings by stating 'Do NOT use to read back the shortlist (use list_saved_sites), download it (use export_dataset), or score a site (use score_facility).' An agent can select this tool correctly 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?

The description gives explicit when-to-use context ('Answers "remember this parcel for me"...'), a named prerequisite ('call claim_free_key FIRST'), three named exclusions with alternative tools, and a follow-up workflow (pass the returned id to set_site_alert). This fully routes the agent on when to use it versus alternatives.

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