RFC status and replacements

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

Annotations already carry readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond annotations: the 20-item batch limit, acceptance of varied identifiers (RFC number, BCP, STD, draft name), and the fact that it resolves the full replacement chain to its end. No contradiction with annotations.

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 dense, front-loaded sentence states the scope and return fields, followed by a single usage directive. Every clause earns its place; there is no filler or repetition of schema 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 structure need not be spelled out, and annotations cover the safety profile. The description explains the input domain, the batch limit, and the resolved output semantics. Minor gap: it does not describe behavior for invalid/unknown identifiers, but this is acceptable given the output schema and annotations already carry significant weight.

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% and the schema only says 'array of strings' with maxLength 100. The description fully compensates by specifying exactly what the ids array accepts: RFC numbers (RFC 2616), BCP 14, STD 97, or draft names. This is critical semantic detail the schema does not provide, and it is complete.

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?

The description uses a specific verb ('get') with a clear resource (RFC status/replacements) and enumerates the exact fields returned: title, status, current-ness, obsoletes, replacement chain, updates, and links. It clearly distinguishes from siblings (iana_lookup, rfc_section, search_rfcs) since none of those cover status/replacement-chain resolution.

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?

Provides an explicit trigger: 'Use before citing or implementing an RFC.' This tells the agent when to reach for the tool. However, it does not name sibling tools as alternatives (e.g., 'for a section, use rfc_section') or state when not to use it, leaving the exclusion logic implicit.

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