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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is fully consistent while adding substantial context the annotations cannot: deleted apps are excluded, and any project member including viewers can call it. It enumerates the returned fields and their semantics (status values, errorMessage, source/branch/sync state, viewerUrl), which matters because there is no output schema.

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?

Purpose and scope are front-loaded in the first clause, and nothing is redundant. The middle field enumeration is a long run-on list, but it earns its place given the absence of an output schema; slightly tighter grouping would read better.

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 compensates by documenting the returned fields and their meanings, and it covers permissions, exclusions, and the alternatives. Nothing an agent needs in order to choose and call this tool 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?

There is a single parameter with 100% schema description coverage pointing to fastero_list_projects, so the schema already carries the semantics. The description only implies the project scoping; it adds no format or sourcing detail beyond what the schema states. Baseline 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 a project's Streamlit apps") plus an explicit scope qualifier ("without their files"), which immediately separates it from fastero_get_streamlit_app and the log reader. An agent can distinguish it from all siblings without opening any 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?

"Use it to find an app or see which are up" gives the positive selection condition, and the next sentence names both alternatives with the exact cases that select them (reading files / checking live status vs. reading start-up output). It also states exclusions: deleted apps are not listed.

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