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

Annotations already indicate readOnly and idempotent, but the description adds non-obvious behavior: cursor validity depends on exact same query/filters/state, ranking covers only the top 200 candidates, and rankMode 'image' changes the ranking unit to individual captions. These are real behavioral constraints an agent needs before calling.

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 dense sentences, each earning its place: core purpose, routing guidance, then paging/ranking caveats. The main action is front-loaded and there is no redundant restatement of schema fields.

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?

For a high-complexity tool with an output schema present, the description supplies selection context, visual-query behavior, cursor rules, and ranking limitations. Remaining parameter details live in the schema, so nothing critical is missing for correct invocation.

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 50%, but the schema already documents many filter fields in detail. The description adds meaning beyond the schema by explaining semantic query scope, rankMode image behavior, and the coupling between cursor, query, filters, and state. It does not describe every parameter, but the schema covers the rest.

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 and resource: 'Search the user's Stashr bookmarks semantically.' It also distinguishes itself from sibling fetch by naming it explicitly and by describing the image rankMode path to view_media. This is enough for an agent to tell it apart from list_bookmarks and fetch.

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?

Gives explicit routing guidance: 'Use this before fetch when finding saved knowledge by meaning, wording, tag, author, platform, or content type.' It also explains when to use rankMode 'image' and how to follow through to view_media, plus practical advice to narrow with filters instead of paging deep.

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