List Context Sources

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds that this is a broad discovery probe returning content categories and discovery surfaces, but says nothing about response shape, ordering or what a cold client should do with the result.

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 with zero filler, and the primary purpose is front-loaded before the audience qualifier. Nothing is repeated from the title or annotations.

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 zero-parameter, read-only discovery tool with annotations covering safety, the description gives enough to call it: it names the categories and surfaces returned. With no output schema, a fuller sketch of the returned structure would have pushed this higher.

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?

The tool takes zero parameters, so the schema carries no semantics to compensate for; the baseline of 4 applies. The description's enumeration of content types is about return content, not input, so it neither helps nor hurts here.

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 discovery action and enumerates the resource categories it covers (AGENTS.md, memory, identity) plus the dimensions it reports (media types, discovery surface). It implicitly reads as the umbrella lister over siblings like read_agents_md, list_agents_md_sections and whoami, but never names them, so it falls short of a 5.

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?

"For a client connecting cold" gives a genuine usage context (session-start discovery), which is more than nothing. However, it offers no explicit alternatives or exclusions, and with near-overlapping siblings (list_agents_md_sections, read_agents_md, whoami) an agent could still pick the wrong tool.

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