upc_library_filters

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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=true. The description adds genuine context beyond them: it uses only the local verified library session, rejects any URL/token/cookie/header input, and warns that captcha_required=null means unconfirmed rather than disabled. That caveat is valuable, but there is mild tension with openWorldHint=true since the text stresses purely local session state.

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 first sentence delivers the payload, followed by two short constraint/caveat sentences. No filler, and the null-semantics warning is placed where an agent will read it before interpreting results.

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 no-argument, read-only filter lookup with no output schema, the description names the returned concepts (dates, buildings, captcha setting) and flags the one ambiguous value. Enough for an agent to call and interpret it; only the return shape of 'dates' and 'buildings' stays unspecified.

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?

With a single trivial parameter (session_ref, const 'self', default 'self') and 0% schema description coverage, the baseline is already high. The description's phrase 'the bound user's' explains that the caller cannot name another user, which clarifies the const-value semantics the schema leaves implicit.

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: reads the bound user's bookable dates, buildings and captcha setting. That is clearly distinct from the sibling booking/mutation tools (upc_library_book, upc_library_reservations) and room/seat lookups, though the description never explicitly frames itself as the preflight/metadata call those siblings depend on.

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?

No when-to-use or when-not-to-use guidance and no mention of alternatives. The agent must infer that this is a discovery call to run before upc_library_times or upc_library_book based on the field names alone, and the description offers no trigger condition or ordering advice.

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