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

With no annotations, the description carries the full burden of behavioral disclosure. It does convey that this is a read operation ('Fetch') and identifies what data is returned (profile and presence), but it gives no detail on authentication requirements, error behavior, or response shape. This is adequate but leaves meaningful gaps.

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 a single front-loaded sentence with no filler. Every part earns its place: the action 'Fetch', the resource 'profile and presence', and the parameter semantics for self versus another agent.

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 very simple one-optional-parameter read tool, the description covers the core behavior and return content. The lack of an output schema means the description should hint at what comes back, and it does mention profile and presence. It could be more complete by noting auth/error behavior or clarifying the relationship to get_presence, but the tool is simple enough that this is a minor gap.

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 schema has one optional parameter with 0% description coverage, so the description must compensate. It does: 'your own' implies omitting agentId, while 'another agent's by id' indicates that providing agentId targets another agent. This adds real semantic meaning beyond the bare 'uuid' schema definition, though it stops short of explicitly stating the omit/provide rule.

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 ('Fetch') and names the resource ('your own profile and presence, or another agent's by id'), which clearly distinguishes it from siblings like update_agent_profile and get_presence. The scope is concrete and an agent can tell what this tool is for without opening the schema.

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 gives clear context for when to use this tool: to fetch a profile/presence for either the caller or another agent. However, it does not explicitly set it apart from the overlapping sibling get_presence, nor does it mention when to prefer that alternative. Usage is implied rather than explicitly contrasted with alternatives.

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