Read a profile

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds valuable behavior context: it explicitly accepts multiple account identifier formats and resolves accounts the instance has never seen, which informs the agent about potential network/remote resolution and return completeness. No contradictions.

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 sentences each earn their place: the first summarizes the return contents, the second specifies accepted input formats, and the third highlights the remote-resolution behavior. The most critical information (what the tool returns) is front-loaded, with no fluff or redundancy.

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 two parameters, the description is complete: it states what is returned, what inputs are accepted, and how unknown accounts are handled. The output schema is absent, but the description lists the key result fields sufficiently for an agent to understand the return value. No critical operational detail 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?

Although the schema has only 50% description coverage (the required 'acct' parameter lacks a schema description), the description compensates by clearly stating that the tool accepts '@user@instance', a bare local username, or a numeric id. This directly maps to the 'acct' parameter and provides the format information the schema omits. The 'account' parameter is already described in the schema, so the description adds meaning beyond it.

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 uses a specific verb ('get') with a clear resource ('full profile for any account') and enumerates what is included (bio, counts, metadata fields, verification state, mutual follow status). It clearly distinguishes itself from sibling tools like get_account_statuses or get_relationships by focusing on the complete profile object.

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 when to use it: whenever a full account profile is needed, regardless of whether the account is known to the instance. It does not explicitly mention alternatives or exclusions, but the context is clear from the enumerated content and the note about resolving unseen accounts. This meets the 'clear context, no exclusions' level.

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