Verify credentials

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, covering the safety profile. The description adds value beyond that by revealing it performs an authentication check ('confirm credentials work') and returns a 'live profile' with follower counts, giving behavioral context about freshness and failure modes.

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 description is two sentences with no filler. The primary function is front-loaded, followed immediately by concrete usage triggers. Every clause earns its place.

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 read-only tool with one optional parameter, no output schema, and strong annotations, the description covers the essentials: what it does, what it returns (profile, follower counts, handle, DID), and when to invoke it. Nothing an agent needs to call it correctly 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?

Schema coverage is 100%, and the schema's parameter description is rich: it explains how to specify the account, the default behavior, and directs the agent to list_accounts. The tool description itself adds no additional parameter semantics, so the baseline of 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 states a specific verb-resource pair: 'Authenticate and return the live profile for a connected account, including follower counts.' It also provides concrete use cases ('confirm credentials work' and resolving 'me'/'my'), which clearly differentiates it from siblings like get_profile or list_accounts.

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 explicitly says when to use this tool: 'Use this to confirm credentials work, or when the user says "me" or "my" and you need their handle and DID.' It also references list_accounts in the parameter description, guiding the agent on how to handle the account parameter.

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