source_details

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered. The description adds that the result spans coverage, access and search tips, but says nothing about permissions, rate limits, or coverage gaps; an output schema exists so return-value detail isn't required.

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 sentence with the resource scope front-loaded and the id-provenance hint in a compact parenthetical. Every clause earns its place.

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 an output schema present, the return shape need not be described, and the description conveys what information the tool surfaces. The only real gap is the unaddressed lang parameter and the absence of any exclusion guidance against sibling guide tools.

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 must carry the burden, and it only partially does: 'by id from find_sources' gives useful semantics for source_id. The 'lang' parameter (enum en/ru, default en) is never mentioned, leaving localization behavior undocumented.

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 and scope: 'Everything about one source from the catalogue', enumerating the content types (coverage, access, search tips). It implicitly separates itself from the lookup sibling find_sources by referring to it as the id provider, though it doesn't name an explicit contrasting alternative.

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 parenthetical '(by id from find_sources)' gives a clear prerequisite: you must run find_sources first to obtain the id. That is real routing guidance, but there is no statement of when-not to use it or which sibling to prefer for other record/catalogue questions.

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