upload_app_screenshot

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

With no annotations, the description carries the full behavioral burden. It does add real value by disclosing the compound three-step flow (reserve, chunk upload, commit) and that an md5 checksum is used, which tells the agent this is not a single atomic write. It omits auth/permission requirements, file size or format validation, failure/rollback behavior, and rate limits.

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?

Two tight sentences, front-loaded with the core action before the mechanics. The second sentence earns its place by explaining the hidden multi-step flow. The md5 reference is slightly opaque about what the checksum is computed over, a minor imprecision.

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?

No output schema and no annotations, so the description is the sole source of behavior. It explains the upload pipeline adequately but says nothing about the return value (e.g. does it return the created screenshot id?), permission scope, or error handling, leaving meaningful gaps for a mutating file-upload tool.

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 100%, so both parameters (filePath, appScreenshotSetId) are already documented in the schema. The description mentions 'local PNG file' and 'screenshot set', echoing the schema without adding format, size, or path constraints beyond it. 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 (upload) and resource (local PNG into a screenshot set), which is enough to separate it from siblings like create_app_screenshot_set or delete_app_screenshot. It never names an alternative explicitly, so it stops short of full sibling differentiation.

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: 'upload into a screenshot set' suggests a set must already exist, which distinguishes it from set creation. There is no explicit when-to-use, when-not-to-use, or prerequisite statement (e.g. set must exist, file must be PNG), leaving the agent to infer.

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