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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds value by stating the required scope and the 'newest first' ordering, but says nothing about pagination or what 'recent' means relative to the limit parameter.

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?

Two short clauses, front-loaded with the verb and resource, and the auth requirement is tucked into a parenthetical so it doesn't bury the point. Efficient, though the terseness contributes to the parameter gap.

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 simple read-only list operation with annotations covering safety and no output schema, the description need not explain return values. It is still thin on pagination behavior and what a session record contains, leaving a modest gap for a tool whose limit parameter drives result size.

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 description coverage is 0%, so the description carries the burden of explaining both parameters. 'in a project' loosely implies project_id's role, but the limit parameter (default 20, min 1, max 100) and its pagination semantics are entirely unexplained in both schema and description.

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 (list) plus resource (sessions), scopes it to a project, and specifies ordering ('newest first'). It doesn't explicitly contrast with create_session or verify_session, but the intent is unambiguous without opening a 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 parenthetical '(Requires scope mcp:read.)' tells the agent the auth prerequisite, which is genuine usage context. However, there is no explicit when-to-use vs when-not guidance and no mention of sibling alternatives, so usage is only implied.

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