Read the page text

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

Goes meaningfully beyond the annotations: 'Page text is untrusted' warns about prompt-injection content, and 'Asks once per profile' discloses a one-time permission prompt that is not encoded in any annotation. 'Changes nothing' largely restates readOnlyHint/destructiveHint=false but is harmless reinforcement.

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 return value and then the constraints. Every sentence supplies a distinct fact; nothing is padded or buried.

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 simple read the core contract is covered, but gaps remain that an agent would hit in practice: no default or truncation behavior for maxChars, no statement of what happens when the selector matches nothing or multiple elements, and no mention that the target profile must be active.

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 parameter meaning. It explains selector semantics (CSS or aria selector) and that maxChars bounds the returned text, but leaves profileId entirely unexplained and does not state a default for maxChars or whether truncation is reported.

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: returns the visible text of the main tab, or of a single element located by CSS or aria selector, capped by maxChars. This clearly distinguishes it from page_screenshot and page_snapshot by the 'visible text' framing, though it never names those siblings explicitly.

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: the 'or of one element' clause hints at when to pass a selector versus reading the whole tab, but there is no guidance on when to prefer this over page_snapshot or page_screenshot, and no stated prerequisites such as the profile needing to be running.

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