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

Annotations already declare readOnly/idempotent/non-destructive, so the description only needs to add behavioral context, which it does: versions contains only the currently-shown version, and allVersions 'can be large' warns about payload growth. It does not cover error or permission behavior, but for a read tool that is a minor gap.

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?

Four short sentences, front-loaded with the verb and resource, then return shape, then parameter guidance, then usage/anti-usage. No sentence is filler; each one changes how an agent would call the tool.

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 values need not be re-explained, yet the description still names the key data path (data.versions[].code) and the cross-tool handoff value. Nothing required to call this read tool correctly is missing.

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 adds real meaning beyond the schema by explaining what versions actually contains versus allVersions, and by noting that the returned screenId is the value to pass to design, which is chaining guidance the schema cannot express.

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 and resource ('Fetch a screen's generated HTML') and immediately resolves the name/semantics mismatch (tool is get_component but the artifact is a screen's HTML). It explicitly distinguishes itself from the design-run siblings with 'not to check whether a design run worked'.

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?

Gives an explicit positive use case ('use this for a build handoff') and an explicit exclusion ('not to check whether a design run worked'), which routes the agent away from get_design_run. It also gives a conditional path for allVersions ('use allVersions for the full history').

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