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

Annotations already declare readOnlyHint and destructiveHint, and the description adds 'Read-only, costs nothing' plus a detailed account of the two behaviors (no argument vs. platform). It does not contradict annotations and provides useful operational context beyond the structured fields.

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?

Three dense sentences, front-loaded with purpose, then behavior, then when-to-use. Every clause adds value; no filler or redundant restating of the schema.

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 one-optional-parameter introspection tool with an output schema, the description fully covers what happens with and without the parameter, what the return contains, and when to call it. Nothing essential is missing.

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 has one optional 'platform' with no description (0% coverage), so the description carries the burden. It clearly explains that omitting platform lists every supported platform, while passing platform returns platform-specific fields like account-id, row levels, breakdown dimensions, and entity types.

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?

Description uses a specific verb ('Explains') and names the exact resource: the unified read tools' capabilities. It distinguishes two modes (no argument vs. platform) and mentions the specific functions it introspects (get_report / list_entities), making it clearly different from sibling tools like get_report or list_entities.

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?

Gives an explicit call condition: 'Call this whenever you are unsure which level/breakdown/entity name to pass.' This directly tells an agent when to invoke describe instead of guessing parameters or trying sibling tools.

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