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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered; the description adds real value by disclosing that absence types, reasons and notes are omitted from the response. It does not cover not-found behavior or auth/permission requirements. 'Read-only Smartplan Pro API' largely restates the annotation.

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 short, front-loaded clauses; the key scope statement comes first and the field-exclusion caveat follows. The final 'Read-only Smartplan Pro API' sentence is largely redundant with annotations.

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 must convey what comes back; it says what is excluded but not what fields are included, and does not address error behavior. Adequate to call correctly, but thin for an agent that must reason about the returned payload.

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?

Only one parameter (id) and the schema carries 0% description coverage, so the description is the only source of meaning — it says only 'by ID', leaving the format, allowed characters and the 80-character limit unexplained (the schema has the pattern but no prose). This is the minimum viable level.

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+resource: retrieves a single absence by ID, scoped to the selected account. The singular framing distinguishes it from smartplan_list_absences, though the sibling is never named explicitly.

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?

Usage is only implied — an agent can infer this is for single-record lookups, but there is no explicit 'use when you have an ID / do not use for browsing' guidance and no mention of the list alternative. The 'excludes absence types, reasons and notes' note hints that other tools may be needed for related data, but it is not framed as routing advice.

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