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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds useful content-level context by naming the snapshot metrics (DA, visibility, organic keywords, traffic, backlinks), but says nothing about ordering, limits, or behavior for a site with no tracked competitors.

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, front-loaded sentence with no filler; the parenthetical field list is the most valuable part since there is no output schema. Slightly dense and could be split, but nothing is wasted.

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?

With no output schema, the description compensates by naming the returned fields, and the single input parameter is documented in the schema. It lacks minor details (result ordering, empty-state behavior, count limits) but is sufficient for correct invocation.

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?

Only one parameter (site_id) and schema description coverage is 100% ('UUID of the site'), so the schema fully carries the parameter semantics. The description adds nothing beyond what the schema provides — the correct baseline here is 3.

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 states a specific resource ('Tracked competitors for a site') and enumerates the snapshot fields returned, which is clear enough to distinguish it from the sibling add_competitor (a mutation). It stops short of an explicit verb like 'List/Retrieve', but the intent is unambiguous.

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?

There is no when-to-use guidance, no mention of prerequisites (e.g. that competitors must first be added via add_competitor), and no alternatives named. The word 'Tracked' hints at scoping to already-added competitors, but the agent must infer this.

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