instagram_download_media

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

Annotations already provide readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds meaningful context by clarifying that the write is to local disk, not to Instagram, and that it is safe in read-only mode. It also discloses behavior for albums (one file per item). This goes beyond the annotations without contradicting them, earning a 4.

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?

The description is tightly written: a one-line overview, a safety note, then structured Args and Returns. Every sentence earns its place, and the core action is front-loaded. No redundant detail; the format aids quick comprehension.

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?

Given the availability of an output schema (which details return structure) and annotations for idempotency/destructiveness, the description covers the essential usage context: what it downloads, where it writes, and album handling. It omits error-handling or prerequisites, but these are minor relative to its coverage. A 4 reflects strong completeness without being exhaustive.

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 'media' and 'folder' are already documented. The description repeats the same info ('A post URL, shortcode or media id' and 'Where to write the files') but adds no additional nuance. With high schema coverage, the description adds marginal value, meriting the baseline 3.

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?

The description clearly states the verb (download), the resource (a post's photo, video, or album), and the destination (local disk). It differentiates from siblings like instagram_get_media by explicitly noting it writes to local disk and not to Instagram, making the tool's purpose unambiguous.

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?

The description provides a clear context: 'Writes files to the machine running this server, not to Instagram, so it is safe in read-only mode.' This indicates when to use it (e.g., when a local copy is needed) and subtly aligns with alternatives (e.g., if you only need metadata, use get_media). However, it does not explicitly state exclusions or name alternative tools, so it stops short of a 5.

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