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

Beyond the readOnly/openWorld/idempotent annotations, it discloses two real behavioral traits: videos are silently excluded from results, and an empty list is ambiguous because it can mean either no photos or that Google did not answer. That failure-mode disclosure is genuinely useful and not derivable from 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?

Three short sentences, front-loaded with what is returned, followed by the follow-on tool routing and the empty-result caveat. No repetition of the title and no wasted clauses.

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 two-parameter read tool with full schema coverage and no output schema, the description supplies everything needed: what comes back, what is excluded, how the result feeds sibling tools, and how to interpret an empty response.

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 schema already documents both accountId and locationId, including the 'omit for the one selected in Ignix' default. The description adds no parameter-level meaning, so the baseline of 3 applies.

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 ('List the photos on a Google Business listing') and immediately scopes it by excluding videos, then enumerates the returned fields (mediaId, url, category, caption). This is clearly distinguishable from the many other list_* siblings because it names the GBP photo domain 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?

Routes the agent to the correct next tools: use the mediaId with remove_gbp_photo, and add new ones with add_gbp_photo. That is clear contextual guidance for the follow-on workflow, though it does not state an explicit when-not-to-use case or a prerequisite such as fetching accountId from list_accounts (that hint lives only in the schema).

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