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

Annotations already establish readOnly/idempotent/non-destructive, and the description adds real behavioral context beyond them: results are data-only with nothing surfaced to the user, the resultId must be handed to sightglass_show (which does not re-search), and the call works unauthenticated before sign-in.

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 core definition, then parameter routing, then the show/auth workflow. Every sentence carries information, though the workflow and auth notes make it longer than a minimal definition.

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?

With no output schema, the description still covers the key return contract (data-only, resultId, show call) and auth requirements. It leaves the projectId/workspaceId plan-applicability behavior implicit for a 7-param, zero-required tool, which is the main gap.

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 57%, and the description clarifies the highest-stakes parameter (`slug` switches to a single-technology view) and ties the default directory output to the ranking/sort concept. It does not explain sort's enum options, limit, search, or the projectId/workspaceId plan-selection semantics, so it only partly compensates.

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 resource and scope: 'the apps and vendors detected on tracked brands' sites (Shopify, Klaviyo, Recharge…), ranked by how many brands use each.' Concrete examples plus the ranking basis let an agent distinguish it immediately from sibling finders like find_ads or find_site_pages.

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?

Explicit routing: pass `slug` for one technology's stats, and pass the technology name as `technologies` to sightglass_find_ads or sightglass_find_site_pages to get the underlying brands/ads. It also states the follow-up show workflow and that no Replo account is needed, so when/when-not is fully covered.

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