freeagent_get_invoice

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description builds on that by specifying what 'full' means (including line items). It adds useful behavioral context beyond the annotations without contradicting them.

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?

A single, succinct sentence that front-loads the verb and resource, with zero wasted words. It is immediately scannable and clear.

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 simple, single-parameter read-only tool with strong annotations, the description covers the essential purpose and return scope. No output schema exists, so the mention of line items helps set expectations. The tool's simplicity means nothing critical is missing.

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?

The single parameter invoiceId is fully described in the schema (100% coverage), including its pattern. The description does not need to add parameter-level detail, and it doesn't, but it reinforces that the tool fetches by ID. Baseline 3 is appropriate.

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 clearly states a specific action ('Fetch') targeting a single resource ('a single FreeAgent invoice') and adds a key differentiator ('in full, including its line items'). This distinguishes it from sibling tools like freeagent_list_invoices.

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 implies usage when a specific invoice ID is known and full detail (including line items) is needed. It does not explicitly name alternatives or exclusions, but the clear scope ('single') and sibling context provide adequate guidance.

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