ECC overview

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 useful context on the payload contents (four domains, counts, sources), giving the agent a sense of what a summary returns beyond a bare lookup.

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 tight sentences: the first enumerates the content, the second is a one-line routing cue. No filler and the key detail is front-loaded.

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 read-only, no-required-param overview tool with no output schema, the description adequately conveys scope and content. Nothing critical is missing, though a note on how it relates to the list/search siblings would make it fully self-sufficient.

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 coverage is 100% and both parameters (lang, response_format) are fully documented with enum values, so the schema does the heavy lifting. The description adds nothing about language or output format selection, so the baseline of 3 applies.

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 resource (the ECC-2:2024 framework overview) and enumerates what it covers: the four domains, subdomain/control counts, and official sources. It is clearly distinct from listing or search siblings, though it doesn't name them directly.

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?

'Start here' gives clear positioning as the entry-point tool for the ECC family, which is real usage guidance relative to siblings like ecc_list_domains or ecc_search_controls. It does not spell out when NOT to use it or name alternatives explicitly.

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