freshbooks_decline_estimate

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

Annotations declare readOnlyHint=true and openWorldHint=false, and the description substantially enriches that: it guarantees no request is ever sent, that the call always fails, and gives the underlying domain reason (no declined state, no decline webhook, only draft/sent/viewed/replied/accepted/invoiced). This is exactly the kind of context annotations cannot convey.

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?

The critical fact — the tool always fails and never sends a request — is front-loaded, and each following clause adds a distinct piece of evidence (status set, missing action, missing webhook, rationale). It is longer than most definitions but no sentence is filler.

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?

There is no output schema, and the description compensates by describing what the call yields (the reason plus alternatives). For a deliberately non-functional stub, an agent has everything it needs: it knows the call is safe, always fails, and why to use it.

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 description coverage is 100% for the single required 'id' parameter, so the schema already carries parameter meaning. The description adds nothing about the id (e.g., that it is accepted but unused), which is the baseline 3 case.

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 opening sentence states exactly what the tool does: it always fails, never sends a request, and is not supported by the FreshBooks API. It also contrasts itself with the accept path ('there is no action_deny or action_decline counterpart to action_accept') and with update_estimate-style writes, so an agent can distinguish it from the real estimate tools.

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?

It explicitly says when to call it ('Call it to get the alternatives') and explains the intent ('so this answers with the reason instead of a plausible-looking write that changes nothing'). It doesn't name the specific substitute tool (e.g., update_estimate for status changes), so routing is implied rather than fully spelled out.

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