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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds what they cannot: the required ExtensionDash account and concrete login commands, plus the shape and subtleties of the returned data (e.g., whether the store rounded the user count). With no output schema present, disclosing the return contents is genuinely load-bearing information.

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?

Front-loaded with the return shape, then usage, then auth—a sensible order with no filler. It runs slightly long, and the two client-specific login examples are more verbose than strictly necessary, but every sentence still carries actionable content.

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 zero-parameter, no-output-schema list tool, the description supplies everything needed: what comes back, when to call it, and the authentication requirement. No return-value documentation is missing and no pagination concerns arise since the call is unparameterized.

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 takes zero parameters, so the baseline is 4. The description correctly implies the call is unparameterized and instead scopes the result set to 'this token's owner's tracked extensions', which is the one piece of scoping semantics an agent needs.

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?

States a specific verb+resource ('Every extension this token's owner tracks') and enumerates exactly what each entry contains: user count (with rounding caveat), 7-day change, rating, ratings count, category rank. This distinguishes it cleanly from get_extension (single extension) and list_competitors/list_keywords (other list 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?

Provides clear entry-point guidance ('Start here when this connection has an account') and explains the downstream dependency ('every tracking tool takes an extension_id from this list'), plus the account prerequisite. It does not, however, name a specific sibling as an alternative or state a when-not-to-use condition, so it falls short of a full 5.

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