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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the agent knows this is a safe, closed-world read operation. The description adds no additional behavioral context (e.g., freshness, pagination, or auth requirements), but since annotations cover the safety profile, the description's minimal addition is acceptable.

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, focused sentence that front-loads the purpose ('Return the core profile') and lists the included fields without any wasted words. The structure is efficient and easy to parse.

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?

Given the tool's simplicity (no parameters, read-only, output schema present), the description fully covers what the tool does. Any return-value specifics are presumably defined in the output schema, which the description need not repeat.

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 tool has zero parameters, so the input schema provides no semantics to enhance. Per the rubric, the baseline for 0 parameters is 4, and the description correctly omits any parameter explanation since none exist.

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 the verb 'Return' and the resource 'core profile', then enumerates the specific components (identity, headline, etc.). It is immediately distinct from sibling tools that handle services, certifications, experience, projects, publications, or articles.

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 context by naming the core profile fields, which contrasts with the sibling list tools. However, it does not explicitly state when to use this tool versus alternatives (e.g., 'use this for the main profile, not for lists'). This is clear context without exclusions.

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