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

Annotations declare destructiveHint=true and readOnlyHint=false but say nothing about modes, prerequisites, or side effects; the description fills exactly those gaps. It discloses the read-only mode (privateKey alone returns the current entry), the content requirements for a new entry, the condition under which the listing persists ('listed while the lambda is online'), and the expected writing style.

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?

Front-loaded with what the tool does, then the gating condition, then the read mode, then entry requirements. Reasonably tight, though the style-prescription sentence ('no marketing language, no superlatives, no exclamation marks, no emoji') is somewhat verbose relative to the functional content.

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 no output schema, the description carries the return-value burden and does so ('returns the current entry'). All five parameters are covered, prerequisites are stated, and the destructive/online-listing behavior is clear, leaving nothing an agent needs before invoking it.

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%, so the baseline is 3; the description exceeds it by explaining parameter-combination semantics that the schema cannot express on its own (privateKey alone = read; title/description/picture required for a new entry; remove takes it off). It does not add format details for image beyond what the schema already documents.

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 stack and resource ('List a lambda on the public showcase page, change its entry, or take it off') that is unmistakably distinct from siblings like create_lambda, deploy, or write_code. An agent can identify both the resource and the three modes of operation without opening the schema.

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?

Explicit when-to-use and when-not: 'Not part of building: only do this when the user asks for it', which clearly separates it from the build/deploy workflow siblings. It also implies mode selection ('With only privateKey it returns the current entry'), though no sibling alternative is named for the listing itself.

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