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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description earns credit for disclosing what is returned (status, contents, dates, limits) in the absence of an output schema, but says nothing about error behavior or whether contents are paged or truncated.

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?

One sentence, front-loaded with the verb and resource, and every listed noun (status, contents, dates, limits) adds information rather than padding. No waste.

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 single-parameter read tool with full annotation coverage, this is close to adequate, and the return-field summary compensates for the missing output schema. However, it leaves unresolved what a source is and how to obtain a valid id, which matters given a very large sibling set containing related tools like list_sources and source_report.

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 0% for the single source_id parameter, so the description must carry the burden. It only restates that the input is a 'source id' — already obvious from the property name — with no format, provenance, or example of where such an id comes from (e.g., list_sources).

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 verb ('Read') and resource ('one source') scoped to a single id, which contrasts implicitly with the sibling list_sources. It stops short of naming the sibling or clarifying what a 'source' is in this domain, so an agent can identify the operation but not fully distinguish its role in the broader catalog.

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?

Usage is only implied: 'one source' signals a single-record fetch, which an agent can infer is the counterpart to list_sources. There is no explicit statement of when to prefer this over list_sources or source_report, nor any prerequisite or not-found guidance.

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