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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds a genuine behavioral guarantee not present in annotations: missing facts come back as null/unknown rather than being inferred, telling the agent it can trust gaps in the output. Nothing is said about ordering of results or whether an unpublished/invalid ID errors or returns a null row.

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 sentences, no filler, with the core scope (2-4 tools, side-by-side) front-loaded and the data-integrity guarantee second. Nothing could be removed without losing information.

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?

An output schema exists, so return values need no explanation, and annotations cover safety. Still missing for a comparison tool: what use_case does to the result, whether compared tools should share a category, and how invalid or unpublished IDs are surfaced.

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. It partially compensates for tool_ids by restating the 2-4 count and the 'published' constraint, but the optional use_case parameter (max 60 chars) is never mentioned and its effect on the comparison is entirely opaque.

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?

Names a specific operation (side-by-side comparison) on a specific resource (published GTM tools) and bounds the input size (2 to 4), which implicitly distinguishes it from get_gtm_tool (single tool) and search_gtm_tools (discovery). It never names a sibling outright, and 'facts' leaves the dimensions compared unspecified.

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 '2 to 4 published tools' framing implies this is the multi-tool comparison path, but there is no explicit when-to-use statement and no mention of when to prefer search_gtm_tools to find IDs first or get_gtm_tool for a single record.

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